Chromoendoscopy and ulcerative colitis

Abstract

Background and aimsTimely diagnosis of intraepithelial neoplasias (IN) and colitis-associated colon carcinomas (CRC) is crucially important in the treatment of ulcerative colitis (UC). We performed a randomized, controlled trial to test whether chromoendoscopy (CE) can facilitate early detection of IN and CRC in ulcerative colitisMethodsA total of 263 patients with long-standing UC (8 years or more) were screened for inclusion in the study, 165 of whom were randomized at a 1:1 ratio to undergo conventional colonoscopy or colonoscopy with CE using 0.1% methylene blue. Five mucosal biopsy specimens were taken every 10 cm between the rectum and caecum. Circumscript lesions in the colon were evaluated according to a modified pit pattern classification.ResultsIn the CE group, there was a significantly higher correlation between the endoscopic assessment of degree (P = 0.0002) and extent (89 vs 52%; P < 0.0001) of colonic inflammation and the histopathologic findings, compared with the conventional colonoscopy group. More targeted biopsies resulted in the detection of significantly more IN in the CE group (32 vs 10; P = 0.003). Using a modified pit pattern classification, both the sensitivity and specificity for differentiation between non-neoplastic and neoplastic lesions measured 93%.ConclusionsBased on our prospective, randomized trial, CE permits more accurate diagnosis of the extent and severity of inflammatory activity in UC compared with conventional colonoscopy. In addition, CE with methylene blue provides a novel tool for the early detection of IN and CRC in patients with UC. These findings have important implications for medical and surgical interventions.